The invention is concerned with the preparation of certain ketotricyclic indoles.
The keto tricyclic indole of the formula: ##STR1## is known [Uhle, F., J.A.C.S. 71, 761 (1949)] and an especially useful method for its preparation is disclosed, in J. Chem. Soc., 1121 (1972), by Bowman et al.
A process for preparing the formula A compound which is more efficient and facile than the Bowman process has been discovered. The process is also useful to prepare a C-homo analog where ring C is seven membered.